Pupin coil.



E. THUERMEL.

PUPJN COIL. APPLIICATIONIHLED MAY 22, 1913;

" Patezite'd May 23,1516.

2 SHEETS-SHEET l.

UNITED STATES PATENT OFFICE.

ERICK THUERMEL, OFCHABLOTTENBURG, GERMANY, ASSIGNOR TO SIEMENS &

HALSKE, A. 3., OF BERLIN, GERMAIIY, A CORPORATION OF GERMANY.

PUIPIN con...

'Pupin Coils, of which the following is a specification.

My invention relates to Pupin coils, and

, particularly to those used in telephonic and telegraphic systems such as, for example, that shown in U. S. Patent to Ebeling It has been proposed to provide a fourwire telephone line for enabling three telephonic conversations to be carried on simultaneously or for telegraphing. This fourwire line consists of two pairs of two-wire lines, and may itself be used as a third line. In this .case each of these two-wire lines forms the single line of the third pair of lines. In such or similar systems. it has been proposed to employ a special arrangement of inductive coils and a suitable connecti-on thereof and thereby effectively to provide thewhole' system with Pupin coils. If coils having windings located one beside anotherare employed large resultant and stray fields are produced as soon as the various windings have currents flowing through them in opposite directions. These resultant fields may cause cross conversation from the two-wire line to the four-wire line. and reversely. The stray fields produceeddy currents in the metallic protective caps surrounding the coils and thereby cause losses "of energy which, like interpolated resistover which telegraphic messages are simulances, exercise a damping action on the telephone currents.

The same phenomena occur, of course. also when such coils are used in those Pupin lines taneously sent (simultaneous working). Here also the telegraph current passing throughthe'two branches of the two-wire line in the same direction produces in the coils fields of opposite direction which can only partially neutralize one another. so that disturbant noises produced by telegraphic currentmay possibly occur in the receiver. Also, in the case of ordinary pupinized aerial lines it is important to construct coils which are insensitive to a current passing in the same direction through the two brain-hes of the two-wire line. such as may arise. for

iaiexample, owing to the influence of adjacent Specification of Letters Patent.

Patented May 23, 1916.

. Application filed May 22, 1913. Serial No. 769,185.

tent that their action can be practically neglected. To this end. I'divide those coils which are associated together in pairs into portions, and I arrange the portions one surrounding another, the one coil being located in one or several layers or portions between the layers or portions of the other coil. According to my invention, in each plane transverse to the axis of a coil the number of portions of one coil is different from the number of portions ofthe other coil. This plane tansverse to .the axis of a coil is hereinafter called the winding plane. The portions of the coils which belong to one pair of coils are superposed in.

such manner that as uniform distribution as possible of the fields produced is obtained over each winding plane. Vhenever current flows in each pair of coils in such manner that the coils oPhose one another mag netically, practically no resultant field on} be produced in any of the said planes, Also, the windings have simultaneously practically the same capacity relatively to the core and protective cap.

Several embodiments of my invention are illustrated by way of example in the accompanying drawing, wherein Figure 1 is a diagram of a Pupin coil constructed in well known manner; Figs. 2 and 3 are longitudinal and transverse sections. respectively. showing-one form of the same, and Figs. l and 5 are like views, respectively. showing another known form of Pupin coil: Figs. 6 and 7 are like views,v respectively. showing an improved Pupin coil Y -core K. When a telephone'ciu'rent passes along the two-wire line it flows through the coil A in the direction from a to I) and through the coil inthe direction from c to (Z, as indicated by the arrows shown in full lines, so that the two coils produce like fields. As indicated by the dotted arrows, tlle current of the four-wire line flows through both coils in the same direction, for example from a to b. and from (I to c. The fields which now oppose one another do not however neutralize one another, but at the points (1, (I and b, c considerable leakage of the lines of force occurs toward the protective cap surrounding the coil whereby the above-mentioned disadvantages are occasioned.

Figs 4 and 5 show an arrangement of a Pupin coil in which the one coil A is wound over the other coil- B. In this arrangement no poles can form, it is true, because both coils completely surround the'core, but even now the fields produced cannot entirely "neutralize onev another. This is owing to the areas of section inclosed by the individual coils being unequal. It follows that if the two coils are to possess equal in'ductances the outside coil must have' fewer turns than the inner. Fnder these circumstances the fields produced bv'the two coils cannot neutralize one another and a disturbing resultant field remains which produces an induced current which flows through the coils in series and the appertaining two-wire line like a talking current. Consequently. cross conversation from'the four-wire line-of the two-wire line can occur, and reversely.

Figs. (3 and 7 show a Iupin coil in which. accordingto the invention. the one of the two coils is divided into two portions A A inclosing between them the other c o il B. As

the diagram of connections in .Fig. 8 shows,

the two portions A A are connected in sewas in suchmanner that they produce a magnetization in the same sense; they possess approxiimitelv equal inductances and. both together have the same total inductance as the coil B located between them.

Fig. 9 shows a lupin coil in which the one coil is subdivided into three portions A A A which illtlUSQ between them the other-coil divided into two portions B B. 'As Fig. 10 shows. the portions of each coil are connected in series and likewise in such manner that-they produce fields of the like sense.

In the form represented in Fig. 11 the individual coils are arranged with portions not only one over another.-b11t also beside one another. On the one hal'f'of the core K the one halfB of the one coil is arranged between two portions A A of: the other coil. while on the other half of the core the fonner coil is divided into two portions 13,. B. which surround the second half A of, the other coil. Fig. 1:2 shows the connection of the portions of the coils.

ond two-wire line L may be turn line. A correspondingeicliange of the examples 'of- Iupin. coils Figs. 13 and 14 show the arrangement of a Pupin coil specially suitable for pu'pinizing the four-wire lines The individual coils of this Pupin coil for each 'of the four lines are distributed on the four quadrants on a common core: For the one two-wire line L consisting of tlie oi'itgoing and return line the one portion B of the coil B connected in the return line is arranged on the one quarter of the core-between the one half of the A-coil in the outgoing line divided into two portions. A... A whileon the diametrall v opposite quarter the other halves B and A' of these coils are wound in exa ctlv similar manner. The coils in the secarranged in an analogous manner on the two other quarters of the coresdiametrally opposite one another. F ig..13 shows. however, another possibilitv' of win'dingfor these coils. corre- Fig. 11. Namely. on-the' one quarterof the core are arranged the portions C C -of a coil connected in the outgoing line;'these portions surround the half D of the coil connected in the return line. while on the other quarterof, the core is mounted the remainder C of the former coil between the parts D D. of the coil connected in the reportions of the coils can of course be made with regard to the 'coils A and B. As the diagram of cmmect'ions in Fig. It shows, the individual portions of a coil are connected in series and the coil in the one wire of a t\\'o-\\'ire lin'e produces a magnetization in a sense opposite to that-of the coil connected in the other wile.

"The forms shown in Figs. 6 to 14 are only having iron cores according to the invention. which however can be varied in various \\'a vs.- The various arrangements of coils can also be'advantagcouslyemployed for Pupin coils without iron cores.

I claim:-

. 1. P-upin coil for'telephone lines and the like comprising in combination a pair of coils wound in portions one surrounding another. the number of portions of one coil in any winding plane being one more than the number of portions of the-other coil in the same winding'plane. and the portions of one coil alternating with the portions of theothcr coil.

2. A Pupin coil: for telephone-lines and the'like comprising incombination a pair of coils -wound in three )ortions one. surrounding another. the numierof portions of one coil iii any winding plane being one more '125 than the number of portions of the other coil in the same winding plane, and the two pfll'tlfllb of one coil inclosing the other coil;

3. A Pupin-coil for telephone lines and the like comprising incombination a core 1 and a pair .of coils belonging to different.

lines and .Wound on said core in portions one surrounding another, the portions of one coil alternating with those of the other coil. and the number of portions of one coil in any winding plane being one more than the number ofportions of the other coil in the same winding plane.

1'. A Pupin coil for telephone lines and the like comprising in combination a core and a pair of coils belonging to difierent lines and woundon said core in portions one surrounding another, one or more of the portions of each coil being wound on the one half ofthe core and the remainder on the other halfpthe number of portions of one coil in any Winding plane being 0116 113011? than the number of portions of the other coil in the same Winding plane, and the one or more portions of one coil in any winding plane alternating with the one ormore portions of the other coil in the same Winding plane. I

In testimony whereof I have signed my name to this specification in the presence of two witnesses.

' ERICH THUERMEL.

' 'itnesses:

HENRY HASPER, \VOLDEMAR HAUPT. 

